Fate of Bacillus cereus within phagocytic cells Authors Ivanna S. Rolny Centro de Investigación y Desarrollo en Criotecnología de Alimentos (CCT-La Plata, CONICET), Cátedra de Microbiología, Facultad de Ciencias Exactas, Universidad Nacional de La Plata Silvia M. Racedo Laboratory of Experimental and Molecular Hepatology, Division of Gastroenterology and Hepatology, Department of Internal Medicine, Medical University of Graz Pablo F. Pérez Centro de Investigación y Desarrollo en Criotecnología de Alimentos (CCT-La Plata, CONICET), Cátedra de Microbiología, Facultad de Ciencias Exactas, Universidad Nacional de La Plata Keywords: Bacillus cereus, LAMP1, phagocytosis, virulence, endocytic pathway, intracellular trafficking Abstract In this study we assessed the interaction of different strains of Bacillus cereus with murine peritoneal macrophages and cultured phagocytic cells (Raw 264.7 cells). Association, internalization, intracellular survival, routing of bacteria to different compartments and expression of MHCII were assessed in cells infected with different strains of B. cereus in vegetative form. Association values (adhering + internalized bacteria) and phagocytosis were higher for strain B10502 than those for strains 2 and M2. However, after 90 min interaction, intracellular survival was higher for strain 2 than for strains M2 and B10502. Acquisition of lysosomal markers by B. cereus containing vacuoles (BcCV), assessed by LAMP1 and Lysotracker labelling occurred shortly after internalization. The highest ratio of LAMP1(+)-BcCV was found for strain M2. This strain was able to survive longer than strain B10502 which routes to LAMP1 containing vacuoles to a lesser extent. In addition, strain M2 stimulated expression of MHCII by infected cells. Confocal analyses 60 or 90 min post-infection showed different percentages of co-localization of bacteria with Lysotracker. Results suggest strain-dependent interaction and intracellular killing of B. cereus by phagocytic cells. These findings could be relevant for the pathogenic potential of Bacillus cereus strains.Keywords: Bacillus cereus · LAMP1 · phagocytosis · virulence · endocytic pathway · intracellular trafficking Downloads PDF Published 2018-03-26 Issue Vol. 20 No. 4 (2017) Section Research Articles License Submission of a manuscript to International Microbiology implies: that the work described has not been published before, including publication in the World Wide Web (except in the form of an Abstract or as part of a published lecture, review, or thesis); that it is not under consideration for publication elsewhere; that all the coauthors have agreed to its publication. The corresponding author signs for and accepts responsability for releasing this material and will act on behalf of any and all coauthors regarding the editorial review and publication process.If an article is accepted for publication in International Microbiology, the authors (or other copyright holder) must transfer to the journal the right–not exclusive–to reproduce and distribute the article including reprints, translations, photographic reproductions, microform, electronic form (offline, online) or any other reproductions of similar nature. Nevertheless, all article in International Microbiology will be available on the Internet to any reader at no cost. The journal allows users to freely download, copy, print, distribute, search, and link to the full text of any article, provided the authorship and source of the published article is cited. The copyright owner's consent does not include copying for new works, or resale. In these cases, the specific written permission of International Microbiology must first be obtained.Authors are requested to create a link to the published article on the journal's website. The link must be accompanied by the following text: "The original publication is available on LINK at <http://www.im.microbios.org>. Please use the appropiate URL for the article in LINK. Articles disseminated via LINK are indexed, abstracted, and referenced by many abstracting and information services, bibliographic networks, subscription agencies, library networks, and consortia.
